Lucky_PierreSkyride you'd be the person that may know this then ,.. can you use something like VidBlaster and stream into this from say Huhy's stream output, mix audio (commentary) over it and then stream out of that for the Live stream.
The modules available for VidBlaster home can be set up in such a way that instant replay is possible. Other smarter people may well be able see the further implications of this as well.
I was actually testing out VidBlaster a few weeks ago, and it does seem pretty cool. However it has a couple of other drawbacks that make it impractical to use for the whole vision mixing system. If I can get a hold of a couple of extra capture cards and an extra PC I can probably work it into the i49 setup. For online it's possible but falls under that "horrible hacks that aren't practical long term" category.